Electrical transformer.



G. W. TERHORST. ELECTRICAL TRANSFORMER. APPLICATION FILED AUG-29' m2 1,1 90,481. Patented July 11, 1916.

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GEORGE W. TERI-IORST, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO PITTSBURGH TRANSFORMER COMPANY, A CORPORATION OF PENNSYLVANIA.

ELEC'IRIGAL TRANSFORMER.

Specification of Letters Patent.

Patented July 11, 1916.

Application filed August 29, 1912. Serial No. 717,657.

To all to hom it may concern:

Be it known that I, GEORGE W. TERIIORST, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Electrical Transformers, of which the following is a full, clear, and exact specification.

This invention relates to electrical transformers.

The object of the invention is to provide projections on the core of a transformer in an eliicient and inexpensive manner, the projections serving for securing the windings in position or for other purposes.-

The invention can be best described in connection with the accompanying illustrative drawings of which" Figure 1 is an end elevation of a structure embodying the invention; F ig. 2 is a side elevation of the same; Fig. 3 is a plan of the same; Fig. 1 is a side elevation (partly broken away) of a layer of laminae at a part having a projection; Fig. 5 is a similar view of a layer, the same as that of Fig. 4, but reversed, and Fig. 6 is a similar view of a layer of laminae at a part where there is no projection, this layer being the same as, but reversed fromthe similar layer shown in Fig. 2.

Referring to the drawings, the electric transformer therein illustrated comprises an iron core Ahaving a central opening B and projections C which serve to position and support the electrical windings D, which are on parallel legs of the core, these legs being magnetically joined by cross pieces or yokes as shown.

In building up the core and starting, say, from the right-hand side as it is seen in Fig. 1, a layer as shown in Fig. 2, or in Fig. 6, is formed. These layers as shown are exactly alike being formed of rectangular laminae 1, 2, 3 and 1, but are alternately reversed with relation to each other when placed in position in the core. Assuming that the first layer is like that shown in Fig. 2, then the next layer to the left in Fig. 1, will be like Fig. 6, then there will be a layer like that in Fig. 2 and so on, the core being built up of the alternately reversed laminae as described so that the joints between the laminae are broken. This is continued until that portion of the core is arrived at at which the right-hand (Fig. 1)

sides of the right-hand projections C are to begin, then instead of employing a layer as shown in Figs. 2 or 6, the layer as shown in Flgs. a or 5 is placed at the left of that part of the core formed up to this. point of the alternately reversed layers as shown in Figs. 2 and 6. The layers as shown in Figs. 4 and 5 are the same, being simply reversed when laid in position in the core. Each of the layers of Figs. at and 5 are formed of rectangular laminae, the laminae 2 and 1 being the same as 2 and a of the layers of Figs. 2 and 6. The other laminae of the layer of Figs. 1 and 5 are not the same as the laminae of Figs. 2 and 6. The laminae 1 and 3 are each replaced by two laminae, the lamina 1 being replaced by the two laminae 5 and 6, while the lamina 3 is replaced by two laminae 7 and 8. The lamina 5 and 7 are alike and also the laminae 6 and 8 are alike. The laminae 6 and S are, however, longer than the laminze 5 and 7 and consequently their ends form projections 9 and 10 from the main body of the layer and upon the layer having these projections, being laid upon each other, and alternately reversed, as shownby Figs. 4. and 5, the right-handv projections C at top and bottom, will be formed as is shown in Fig. l and also similar projections from the main body of the core will be formed upon the opposite side of the core from theright-hand projections as shown in Fig. 1. The laying up of the core is continued with the alternately reversed layers of Figs. 1 and 5 until the right-hand projections G are of the desired width. It will be observed that the alternate reversal of the layers of Figs. 1 and 5 serves to break the joints of the laminae and further, the projections of the layer being symmertical about the center of the core, the reversal. of the layer serves to form project-ions upon opposite sides of the core. The desired width of projections having been secured, the laying up of the core then proceeds with the use of layers as shown in Figs. 2 and 6, these layers being alternately reversed as before described, and this procedure is continued until the righthand sides of the lefthand projections as shown in Fig. 1, are reached. Alternately reversed layers of laminae as shown in Figs. 1 and 5 are then employed as before described until these left-hand projections are of the desired width, when the core is completed to the left-hand edge by the use of the layers of the laminae as shown in Figs. 2 and 6, these layers being laid upon each other and alternately reversed as before described.

The core having been laid up as described, the laminae may be clamped together by bolts, screw-caps placed over the ends of the core or by any of the other suitable means well known for this purpose.

In building up the core as described, it will be seen that between each of the projeetions C there will be a space of the width of a lamina between the lamina? projecting from the main body of the core. In order that the projection may be made more solid, these spaces may be filled in with fillers 12, which may be pieces of laminae of the same thickness as those used in the core and cut the same size as the projection. These fillers when inserted between the laminae projecting from the core will make a practically solid projection and the whole may then be bound together by acord 9 about the end of the projection.

It will be observed that in the construc tion shown the laminae which extend from the main body of the core into the projections are sandwiched between the laminae of the main body of the core, and hence a strong and reliable structure is secured.

It is preferably that pieces of insulation 10, which are inserted between the windings D and the projections C shall extend beyond the edges of those projections as shown and similarly it is preferable that pieces of insulation ll interposed between the yoke pieces and the windings D should extend beyond the edges of those yoke pieces, and beyond the edges of the windings.

lVhile the invention has been illustrated in what is considered its best application, it may be embodied in other structures, and is not therefore limited to the construction shown in the drawings. Also although I have described one method of building up the core other methods may be employed without departing from the spirit of the invention.

lVhat I claim is 2- 1. A laminated transformer core having laminated projections, the laminae of the projections being sandwiched with those of the main body of the core and fillers secured be tween the aforesaid laminae of the projections.

A laminated transformer core, windings for said core, said core having an interior opening for the passage of said windings and having projections for positioning said windings, said projections being formed by extensions from certain of the laminae of which said core is composed, the laminae having said extensions being built into the core, and all of the laminae of said core being rectangular.

3. A laminated transformer core, windings for said core, said core having an interior opening for the passage of said windings and having oppositely disposed projections for positioning said windings, said projections being formed by extensions from certain of the laminae of the core at one side thereof and at the opposite side thereof by reversing the layers of the laminae.

l. A laminated transformer core, windings for said core, said core having an interior opening for the passage of said windings and having oppositely disposed projections for positioning said windings, said projections being formed by extensions from certain of the laminae of the core at one side thereof and at the opposite side thereof by. reversing the layers of the laminae, and all of the laminae of said core being rectangular.

5. A layer of laminae for a transformer core having a central opening, said layer having on two opposite sides of said opening laminae of the same size and at each of the other sides of the opening having two laminae, one longer than the other.

In testimony whereof I afix my signature, in presence of two witnesses.

GEORGE 1V. TERHORST.

Witnesses:

L. G. MrroHELL, V7. G. STEELE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, 1). G. 

